A communications device usually includes a plurality of heat emitting elements therein. A heat emitting element generates heat during operation. If the heat is not dissipated in time, when a temperature value in the heat emitting element exceeds a maximum temperature value that the heat emitting element can withstand during normal operation, a service life of the heat emitting element is shortened or the heat emitting element is damaged. To dissipate the heat in time, each heat emitting element corresponds to a separate heat sink in the prior art. After absorbing heat generated by a corresponding heat emitting element, each heat sink located in a central section of the communications device transfers the absorbed heat to an adjacent heat sink. Specifically, a heat sink transfers heat to an adjacent heat sink, and the absorbed heat is finally dissipated by using a heat sink located at an edge of the communications device. However, because end surfaces of two adjacent heat sinks are separated from each other, relatively large thermal resistance exists between the two adjacent heat sinks. Consequently, heat is transferred between the adjacent heat sinks at a relatively low speed. This may further lead to an excessively high local temperature of the communications device, shortening the service life of the communications device or damaging the communications device.